Proppant storage vessel and assembly thereof

ABSTRACT

A proppant storage vessel has a container having a first end wall, a second end wall, a first side wall, a second side wall, a top wall and a bottom wall. The first and second end walls extend between opposite ends of the first and second side walls. The walls define an interior volume of the container. The walls have a rigidity suitable for retaining no less than 30,000 pounds of proppant therein. A top hatch is formed centrally on the top wall and is movable between an open position and a closed position. A bottom hatch is formed generally centrally on the bottom wall of the container and is movable between an open position and a closed position.

RELATED APPLICATIONS

The present application is a continuation of, is related to and claimspriority to, and the benefit of, U.S. Non-Provisional application Ser.No. 14/831,905, filed Aug. 21, 2015, titled “Proppant Storage Vessel andAssembly Thereof,” which is a continuation of U.S. Non-Provisionalapplication Ser. No. 13/949,693, filed Jul. 24, 2013, titled “ProppantStorage Vessel and Assembly Thereof,” now U.S. Pat. No. 9,296,518,issued Mar. 29, 2016 which is a continuation-in-part of U.S.Non-Provisional application Ser. No. 13/660,840, filed Oct. 25, 2012,titled “Proppant Storage Vessel and Assembly Thereof,” now U.S. Pat. No.8,505,780, issued Aug. 13, 2013, which is a continuation of U.S.Non-Provisional application Ser. No. 13/332,937, filed Dec. 21, 2011,titled “Proppant Storage Vessel and Assembly Thereof,” now U.S. Pat. No.8,827,118, issued Sep. 9, 2014, each of which are incorporated herein intheir entireties by reference.

BACKGROUND

1. Field of the Invention

The present invention relates to storage containers. More particularly,the present invention relates to storage container assemblies whereby aproduct in one container can flow to an interior volume of a lowercontainer. Additionally, the present invention relates to containersthat are suitable for the transport, storage and dispensing of proppantstherefrom.

2. Description of Related Art

Hydraulic fracturing is the propagation of fractions in a rock layercaused by the presence of pressurized fluid. Hydraulic fractures mayform naturally, in the case of veins or dikes, or may be man-made inorder to release petroleum, natural gas, coal seam gas, or othersubstances for extraction. Fracturing is done from a wellbore drilledinto reservoir rock formations. The energy from the injection of ahighly-pressurized fracking fluid creates new channels in the rock whichcan increase the extraction rates and ultimate recovery of fossil fuels.The fracture width is typically maintained after the injection byintroducing a proppant into the injected fluid. Proppant is a material,such as grains of sand, ceramic, or other particulates, that prevent thefractures from closing when the injection is stopped.

With the rise of hydraulic fracturing over the past decade, there is asteep climb in proppant demand. Global supplies are currently tight. Thenumber of proppant suppliers worldwide has increased since 2000 from ahandful to well over fifty sand, ceramic proppant and resin-coatproducers.

By the far the dominant proppant is silica sand, made up of ancientweathered quartz, the most common mineral in the Earth's continentalcrust. Unlike common sand, which often feels gritty when rubbed betweenthe fingers, sand used as a proppant tends to roll to the touch as aresult of its round, spherical shape and tightly-graded particledistribution. Sand quality is a function of both deposit and processing.Grain size is critical, as any given proppant must reliably fall withincertain mesh ranges, subject to downhole conditions and completiondesign. Generally, coarser proppant allows the higher flow capacity dueto the larger pore spaces between grains. However, it may break down orcrush more readily under stress due to the relatively fewergrain-to-grain contact points to bear the stress often incurred in deepoil- and gas-bearing formations.

Typically, in any hydraulic fracturing operation, a large amount of suchproppant is required. Typically, it has been difficult to effectivelystore the proppant at the fracturing sites. Additionally, it has beenfound to be rather difficult to effectively transport the proppant tothe desired location. Often, proppant is hauled to the desired locationson the back of trucks and is dumped onsite. Under such circumstances,the proppant is often exposed to adverse weather conditions. This willeffectively degrade the quality of the proppant during its storage.Additionally, the maintenance of proppant in containers at the hydraulicfracturing site requires a large capital investment in storagefacilities. Typically, the unloading of such storage facilities iscarried out on a facility-by-facility basis. As such, there is a need tobe able to effectively transport the proppant to and store the proppantin a desired location adjacent to the hydraulic fracturing location.

In the past, various patents have issued relating to storage andtransport facilities. For example, U.S. Patent Publication No.2008/0179054, published on Jul. 31, 2008 to McGough et al., shows a bulkmaterial storage and transportation system. In particular, the storagesystem is mounted on the trailer of a truck. The storage system includeswalls that define an interior volume suitable for receiving theaggregate material therein. There are hoppers provided at the bottom ofthe container. These hoppers have inclined walls. The hoppers can extendso as to allow the material from the inside of the container to beproperly conveyed to a location exterior of the container. Actuators areused so as to expand and collapse the container.

U.S. Pat. No. 7,240,681, issued on Jul. 10, 2007 to L. Saik, describes atrailer-mounted mobile apparatus for dewatering and recovering formationsand. The trailer is mounted to a truck-towable trailer so as to receivesand therein. The container has a pair of sloping end walls. The backend of the container is suitably openable so as to allow the sand to beremoved therefrom. A pneumatic or hydraulic ram is provided on theforward part of the container so as to allow the container to be liftedangularly upwardly so as to allow sand to be discharged through the gateat the rear of the container.

U.S. Pat. No. 4,247,228, issued on Jan. 27, 1981 to Gray et al.,describes a dump truck or trailer with a pneumatic conveyor. Thecontainer is mounted to a frame on wheels. A hydraulic ram tilts thecontainer for dumping through a rear outlet. A pneumatic conveyor iscarried by the frame with an intake at the rear of the container. A gateallows the solids to be dumped conventionally by gravity or to be blownto a storage facility by the pneumatic container. The container has atop hatch formed therein so as to allow the solids to be introduced intothe interior of the container.

U.S. Pat. No. 2,865,521, issued on Dec. 23, 1958 to Fisher et al., showsa bulk material truck that has an interior volume suitable for thereceipt of bulk material therein. A pneumatic conveyer is utilized so asto allow the removal of such material from the bottom of the container.A pair of sloping walls are provided on opposite sides of the containerso as to allow the bulk material within the container to be passedtoward the bottom of the container. A top hatch is provided on the topof the conveyer. The pneumatic conveyer is connected to the bottom ofthe container.

It is an object of the present invention to provide a proppant storagevessel that allows proppant to be easily transported and stored.

It is another object of the present invention to provide a proppantstorage vessel that allows the proppant that is contained within thestorage vessel to be easily and efficiently discharged through thebottom thereof.

It is another object of the present invention to provide a proppantstorage assembly which allows for the effective storage of proppant atthe fracturing site.

It is another object of the present invention to provide a proppantstorage assembly which allows proppant to be efficiently removed from astacked configuration of containers.

These and other objects and advantages of the present invention willbecome apparent from a reading of the attached specification andappended claims.

BRIEF SUMMARY OF THE INVENTION

The present invention is a proppant storage vessel that comprises acontainer having a first end wall, a second end wall, a first side walland a second side wall. The container also has a top wall and a bottomwall which serve to define an interior volume therein. A hatch is formedon the bottom wall of the container. The bottom hatch is movable betweenan open position and a closed position. A first inclined surface ispositioned in the interior volume. The first inclined surface extendsfrom the first end wall to the bottom hatch. A second inclined surfaceextends from the second end wall toward the bottom hatch. A thirdinclined surface extends from the first side wall toward the bottomhatch. A fourth inclined surface extends from the second side walltoward the bottom hatch. The walls have a rigidity suitable forcontaining at least 30,000 pounds of proppant therein. The container canhave up to 100,000 pounds of proppant therein.

A top hatch formed on the top wall. The top hatch is movable between anopen position and a closed position.

Each of the first and second end walls and the first and second sidewalls have a middle. The first inclined surface has an upper end affixedto the first end wall below the middle thereof. The second inclinedsurface has an upper end affixed to the second end wall below the middlethereof. The third inclined surface has an upper end affixed to thefirst side wall below the middle thereof. The fourth inclined surfacehas an upper end thereof affixed to the second side wall below themiddle thereof.

A first support brace is affixed to the first and second end walls andextends therebetween. A second support brace is affixed to the first andsecond side walls and extends therebetween. A first support member hasone end affixed to the bottom wall and extends angularly upwardly. Thefirst support member has an opposite end affixed centrally to the firstinclined surface. A second support member has one end affixed to thebottom wall and extends angularly upwardly therefrom. The second supportmember has an opposite end affixed centrally to the second inclinedsurface. Each of the first, second, third and fourth inclined surfaceshas a bottom edge positioned adjacent a perimeter of the bottom hatch.The bottom hatch is hingedly affixed to the bottom wall. The bottomhatch resides against the bottom wall when in the closed position.

The present invention is also a proppant storage assembly that comprisesa first container having an interior volume and a second containersupported in spaced relation above the first container. The firstcontainer has a bottom wall having a bottom hatch affixed thereto. Thehatch is movable between an open position and a closed position. Thefirst container has an opening at a top wall thereof. The secondcontainer has bottom hatch formed on a bottom wall thereof. The bottomhatch of the second container is aligned with the opening of the firstcontainer such that a proppant in the first container can flow throughthe hatch thereof into the interior volume of the first container.

In particular, the first container has a top hatch hingedly affixed atthe opening thereof. The top hatch of the first container is movablebetween a closed position and an open position. The bottom hatch of thesecond container has a length dimension. The length dimension isslightly less than a distance between the first container and the secondcontainer. The top hatch of the first container extends in parallelrelation to the bottom hatch of the second container when each of thetop hatch of the first container and the bottom hatch of the secondcontainer are in the open position.

A first spacer is positioned on the top wall of the first container andextends upwardly therefrom. The first spacer abuts the bottom wall ofthe second container. A second spacer is positioned on the top wall ofthe first container and extends upwardly therefrom. The second spacerabuts the bottom wall of the second container. The first spacer is inspaced relation to the second spacer. A pad is positioned against thebottom wall of the first container. The pad supports the bottom wall ofthe first container a desired distance above an underlying surface. Thebottom hatch of the first container has a length dimension. This lengthdimension is less than a desired distance between the bottom wall andthe underlying surface. As such, a portable conveyer can be placedthereunder. The portable container has a surface positioned between thebottom wall of the first container and the underlying surface. Thesurface of the portable container is directly below the bottom hatch ofthe first container.

Each of the first and second containers has a first end wall, a secondend wall, a first side wall and a second side wall. A first inclinedsurface is positioned in the interior volume of the container so as toextend from the first end wall toward the bottom hatch. A secondinclined surface is positioned in the interior volume of the containerso as to extend from the second end wall toward the bottom hatch. Athird inclined surface is positioned in the interior volume so as toextend from the first side wall toward the bottom hatch. A fourthinclined surface is positioned in the interior volume so as to extendfrom the second side wall toward the bottom hatch.

A third container can be supported in spaced relation above the secondcontainer. The second container has a top hatch formed on a top wallthereof. The third container has a bottom hatch formed on a bottom wallthereof. The bottom hatch of the third container is aligned with the tophatch of the second container. Each of the containers is ocean freightcontainer.

In an alternative embodiment of the present invention, the firstcontainer has the first side wall, a second side wall, a first end walland second end wall hingedly mounted to the bottom wall thereof. A firstslot and a second slot are affixed to the bottom wall of the container.The first and second slots are suitable for the receipt of forks of aforklift therein.

The foregoing Summary of the Invention is intended to describe, insummary, the preferred embodiments of the present invention. However,this section is not intended, in any way, to limit the scope of thepresent invention. The scope of the present invention should be definedby the claims herein and their legal equivalents.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 is a side elevational view of the proppant storage assembly inaccordance with the preferred embodiment of the present invention.

FIG. 2 is an end view of the proppant storage assembly of the presentinvention showing, in particular, the portable conveyer located at abottom thereof.

FIG. 3 is a transparent plan view of the proppant storage container inaccordance with the preferred embodiment of the present invention.

FIG. 4 is a plan view showing of the proppant storage container of thepresent invention.

FIG. 5 is a cross-sectional view as taken from an end of the proppantstorage container of the present invention.

FIG. 6 is cross-sectional view as taken across a side of the proppantstorage container of the present invention.

FIG. 7 is a perspective view of an alternative embodiment of theproppant storage container of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIG. 1, there is shown the proppant storage assembly 10 inaccordance with the preferred embodiment of the present invention. Theproppant storage assembly 10 includes a first container 12 having aninterior volume 14 and a second container 16 having a interior volume18. The first container 12 is in spaced relationship to the secondcontainer 16. The first container 12 has a bottom wall 20. The bottomwall 20 has a bottom hatch 22 affixed thereto. The hatch 22 is movablebetween a closed position and an open position (illustrated in brokenline fashion). The first container 12 has an opening 24 at a top wall 26thereof. The second container 16 has a hatch 28 formed on a bottom wall30 thereof. The bottom hatch 28 of the second container 16 is shown asaligned with the opening 26 of the first container 12 such that aproppant within the second container 16 can flow through the hatch 28into the interior volume 14 of the first container 12.

In particular, in FIG. 1, it can be seen that the first container 12 hasa hatch 32 extending over the opening 24 thereof. In particular, thehatch 32 is hingedly mounted to the top wall 26 of the first container12 so as to be movable between a closed position and an open position(illustrated in broken-line fashion). In particular, the bottom hatch 28of the second container 16 will extend downwardly perpendicularly to thebottom wall 30. Similarly, the top hatch 32 of the first container 12will extend upwardly in generally transverse relationship to the topwall 26. The hatches 28 and 32 will be in generally parallelrelationship in this configuration. As such, the hatches 24 and 28 willform a unique and guided flowpath whereby the proppant in the interiorvolume 18 of the second container 16 can flow directly into the opening24 and into the interior volume 14 of the first container 12. The lengthdimension of the hatches 28 and 32 will be less than the distancebetween the top wall 26 of the first container 12 and the bottom wall 30of the second container 16.

A first spacer 34 is positioned on the top wall 26 of the firstcontainer 12 and extends upwardly therefrom. The first spacer 34 abutsthe bottom wall 30 of the second container 16. A second spacer 36 ispositioned on the top wall 26 of the first container 12 and extendsupwardly therefrom. The second spacer 36 abuts the bottom wall 30 of thesecond container 16. The first spacer 34 is in spaced relationship tothe second spacer 36. The spacers 34 and 36 serve to assure a properdistance between the containers 12 and 16 whereby the hatches 28 and 32can be properly opened so as to allow for the flow of proppanttherebetween. A pad 38 is positioned against the bottom wall 20 of thefirst container 12. The pad 38 serves to support the first container 12above an underlying surface 40 (such as the earth). It can be seen thatthe pad 38 is in the nature of a concrete structure that has a base 42embedded into the earth. As such, the pad 38 is configured so as torigidly support the containers 12 and 16 in their desired positionsabove the earth.

Pad 38 support the container 12 in a suitable distance above theunderlying surface 40 such that the hatch 22 can move from its closedposition to its open position while allowing a certain amount of spacetherebetween. As a result, a portable conveyer can be placed below thebottom hatch 22 so as to allow the proppant within the interior volume14 to be discharged therefrom.

A third container 44 is supported in spaced relationship above the topwall 46 of the second container 16. As can be seen, the third containerhas a bottom hatch 48 located on the bottom wall 50 thereof. The topwall 46 has a top hatch 52 hingedly connected thereto. As a result, whenthe bottom hatch 48 is opened and the top hatch 52 is opened (asillustrated in broken-line fashion), the proppant within the interiorvolume 54 of the third container 44 can flow directly into the interiorvolume 18 of the second container 16. Suitable spacers 56 serve tosupport the bottom wall 50 of the third container 44 a proper distanceabove the top wall 46 of the second container 16. Third container 44also has a top hatch 58 that is movable between a closed position and anopen position (illustrated in broken-line fashion).

In the configuration shown in FIG. 1, volumes of proppants can be easilystored at the fracturing site. It is only necessary to stack each of thecontainers 12, 16 and 44 upon one another in the manner described inFIG. 1. Each of the containers 12, 16 and 44 has an exteriorconfiguration similar to that of an ocean freight container. As such,these containers can be easily transported on the bed of a truck, on afreight train or on a ship to the desired location. Because of thisstacking arrangement, special proppant storage facilities are notrequired at the fracturing site. Each of the hatches 28, 32, 48, 52 and58 can be in a liquid-tight sealing relationship over the respectiveopenings thereof when in the closed position. As such, the arrangementillustrated in FIG. 1 of the proppant storage assembly 10 can avoid anyliquid intrusion into the proppant contained within each of thecontainers 12, 16 and 44. Typically, a forklift, or other liftingdevice, can be utilized so as to properly stack the containers. Withinthe concept of the present invention, two containers, three containers,or more can be utilized in the construction of the proppant storageassembly 10. Each of the containers 12, 16 and 44 has an interiorstructure in the nature illustrated in FIGS. 3-6 herein, as will bedescribed hereinafter. The present invention provides a suitably modulararrangement whereby a proppant storage facility can be easilyconstructed on-site. After the fracturing operation is completed, thecontainers can be easily removed from this stacked configuration andtransported to another location. Similarly, if desired, the containers12, 16 and 44 can be suitably replaced by another container so as toprovide the desired proppant to the fracturing site.

FIG. 2 shows an end view of the proppant storage assembly 10 of thepresent invention showing of the present invention. In FIG. 2, it can beseen that the first container 12 is spaced from the second container 16.The second container 16 is suitably spaced from the third container 44.The bottom hatch 22 of the first container is openable so that theproppant within the first container 12 can be discharged through thehatch 22 onto a portable conveyer 60. The portable conveyer 60 can beeasily transported to a location below the hatch 22 of the firstcontainer 12 so as to allow the proppant from the containers to betransported to another location. Each of the containers 12, 16 and 44 isvertically aligned in a stacked orientation. The first container has acapacity for storing 100,000 pounds of proppant. The second container 16and the third container 44 can store 30,000 pounds of proppant. As such,a very large amount of proppant can be provided to the fracturing site,in a simple easy and convenient manner.

FIG. 3 illustrates the interior construction of the first container 12.The top wall of the first container 12 has been removed for the purposesof illustration. The container 12 has a first end wall 70, a second endwall 72, a first side wall 74 and a second side wall 76. The end walls70 and 72 extend between the side walls 74 and 76 so as to define theinterior volume of the first container 12. A first inclined surface 78extends from the first end wall 70 to the bottom hatch 22. A secondinclined surface 80 extends from the second end wall 72 toward thebottom hatch 22. A third inclined surface 82 extends from the first sidewall 74 toward the bottom hatch 22. Similarly, a fourth inclined surface84 extends from the second side wall 76 toward the bottom hatch 22.Lower ends of each of the inclined surface 78, 80, 82 and 84 are alignedwith the perimeter of the bottom hatch 22. The inclining of the sidewalls 78, 80, 82 and 84 serves to assure that the proppant containedwithin the interior volume thereof is suitably funneled toward thebottom hatch 22. Each of the inclined surface 78, 80, 82 and 84 is has asmooth surface so that a constant flow of proppant can occur.

FIG. 4 illustrates the bracing associated with the first container 12 soas to assure the structural integrity of the container. As can be seen,a first support brace 90 is affixed to the first end wall 70 and extendsacross the interior volume of the container 12 to the second end wall72. The first support brace 90 is suitably welded to the end walls 70and 72 so as to provide a rigid structural support therebetween. Asecond support brace 92 has one end affixed to the side wall 74 and anopposite end affixed to the side wall 76. The second support brace 92extends transversely to the first support brace 90. The second supportbrace 92 provides a rigid support for the side walls 74 and 76. Thefirst support brace 90 and the second support brace 92 structurallyenhance the strength of the container 12 so as to as to withstand theweight of the proppant that is contained therein. The second supportbrace 92 can also include another support brace 94 extending between theside walls 74 and 76 in generally parallel relationship to the firstsupport brace 90. Within the concept of the present invention, variousother support braces, in the nature of angle irons, can be utilized soas to suitably support the structure of the container 12.

FIG. 5 illustrates a cross-sectional view of the container 12. As can beseen, the container 12 has the bottom hatch 22 located on the bottomwall 20 thereof. A top hatch 32 is hingedly mounted to the top wall 26thereof. Hatch 32 serves to cover the opening 24 in the top wall 26. Thebottom hatch 22 is hingedly mounted to the bottom surface of the bottomwall 20 and can be suitably latched to the bottom wall 20 so as toretain the proppant 100 therein. The container 12 has its side walls 74and 76 extending vertically upwardly from the bottom wall 20. The firstinclined surface 78 and the second inclined surface 80 are illustratedas funneling the proppant 100 toward the bottom hatch 22. The firstinclined surface 78 has one end mounted adjacent to hatch 22 and anopposite end affixed to the side wall 74. In particular, the inclinedsurface 78 has its opposite end at the side wall 74 located below themiddle of the side wall 74. Similarly, the second inclined surface 80extends from the hatch 22 toward the side wall 76 at a location belowthe middle of the side wall 76. The second support brace 92 isillustrated as extending across the interior volume 14 of the firstcontainer 12 between the side walls 74 and 76.

FIG. 6 shows another cross-sectional view of the first container 12.First container 12 is illustrated also as having the top hatch 32hingedly mounted to the top wall 26 and the bottom hatch 22 hingedlymounted to the bottom wall 20. The third inclined surface 82 extendsfrom the bottom hatch 22 to the side wall 74. The fourth inclinedsurface 84 extends from the bottom hatch 22 toward the side wall 76.Each of the ends of the inclined surfaces 82 and 84 will joined to therespective walls 74 and 76 at a location below the middle of each of theside walls 74 and 76. The first support brace 90 extends between theside walls 74 and 76 so as to provide structural integrity.

In FIG. 6, there is a first support member 102 that extends from thebottom wall 20 upwardly toward a location centrally of the thirdinclined surface 82. Another support member 104 extends from the bottomwall 20 upwardly toward a center of the fourth inclined surface 84.These support members 102 and 104 enhance the strength of the inclinedsurface 82 and 84 so as to withstand the weight and forces impartedthereto by the proppant 100.

FIG. 7 shows an alternative embodiment of the container 110 of thepresent invention. Container 110 includes a first end wall 112, a secondend wall 114, a first side wall 116, and a second side wall 118. Each ofthe end walls 112 and 114 and each of the side walls 116 and 118 areillustrated as extending upwardly from a bottom wall 120.

Within concept shown in FIG. 7, each of the end walls 112 and 114 andeach of the side walls 116 and 118 are hingedly mounted to the bottomwall 120. It can be seen that there are latch members 122, 124 and 126that serve to secure the walls 112, 114, 116 and 118 in their uprightconfiguration. Latch members 122 join the side wall 116 to the end 112.Latch members 124 join the side wall 116 to the end walls 114. Latchmembers 126 secure the end wall 114 to the side walls 118. An additionallatch member (not illustrated) will secure the end wall 112 to the sidewall 118. As such, the structure of the container 110 can be in asand-receiving orientation.

Importantly, since each of the walls 112, 114, 116 and 118 are hingedlysecured to the bottom wall 120, the walls can be pivoted about thehinges so as to overlie the bottom 112 once the latch members 122, 124and 126 are released. A handle 128 is provided on the end walls 112 and114 so as to allow the container 110 to be moved, as desired. Wheels 130extend downwardly from the bottom wall 120 so as to allow the container110 to be rolled to a desired position.

In FIG. 7, there is first slot 132 and a second slot 134 formed on thebottom of the bottom surface 120. Slots 132 and 134 allow for thereceipt of the forks of a forklift therein. As such, the container 110can be moved to a desired location in a simple and efficient manner.

The present application is a continuation of, is related to and claimspriority to, and the benefit of, U.S. Non-Provisional application Ser.No. 14/831,905, filed Aug. 21, 2015, titled “Proppant Storage Vessel andAssembly Thereof,” which is a continuation of U.S. Non-Provisionalapplication Ser. No. 13/949,693, filed Jul. 24, 2013, titled “ProppantStorage Vessel and Assembly Thereof,” now U.S. Pat. No. 9,296,518,issued Mar. 29, 2016 which is a continuation-in-part of U.S.Non-Provisional application Ser. No. 13/660,840, filed Oct. 25, 2012,titled “Proppant Storage Vessel and Assembly Thereof,” now U.S. Pat. No.8,505,780, issued Aug. 13, 2013, which is a continuation of U.S.Non-Provisional application Ser. No. 13/332,937, filed Dec. 21, 2011,titled “Proppant Storage Vessel and Assembly Thereof,” now U.S. Pat. No.8,827,118, issued Sep. 9, 2014, each of which are incorporated herein intheir entireties by reference.

The foregoing disclosure and description of the invention isillustrative and explanatory thereof. Various changes in the details ofthe illustrated construction can be made within the scope of theappended claims without departing from the true spirit of the invention.The present invention should only be limited by the following claims andtheir legal equivalents.

1. (canceled)
 2. A modular container system structurally strengthened totransport and store large volumes of proppant effectively therein tosupply to a fracturing site, the system comprising: a first containercomprising: a first top, a first bottom having a first outlet formedtherein to allow large volumes of proppant to flow therefrom when theoutlet is in an open position, a first plurality of sidewalls coupled tothe first top and first bottom, so as to define a first interior volumeof the first container thereby to store the proppant therein, theproppant having a substantially spherical shape and a tightly gradedparticle distribution, a first plurality of ramps downwardly inclinedand extending inwardly from the first plurality of sidewalls to directthe proppant toward the first outlet when the proppant is storedtherein, and a first hatch movable toward the second container totransition the first hatch to the open position to allow proppant toflow from the first outlet; a second container adapted to be positionedbelow the first container, the second container comprising: a second tophaving an opening formed therein, a second bottom having a second outletformed therein to allow large volumes of proppant to flow therefrom whenin an open position, a second plurality of sidewalls coupled to thesecond top and second bottom, so as to define a second interior volumeof the second container thereby to store the proppant therein, theproppant having a substantially spherical shape and a tightly gradedparticle distribution, a second plurality of ramps downwardly inclinedand extending inwardly from the second plurality of sidewalls to directthe proppant toward the second outlet when the proppant is storedtherein, and a second hatch movable toward the first container totransition the second hatch to an open position, and a distance betweenthe first and second containers is great enough to allow the first hatchand the second hatch to be in respective open positions at the sametime.
 3. The system of claim 2, further comprising a conveyor positionedbelow the second outlet such that proppant exiting the second containerthrough the second outlet is deposited on the conveyor and transportedaway from the second container.
 4. The system of claim 2, wherein one ormore of the first and second containers includes a first plurality ofstructural supports comprising a first plurality of support braces, thefirst plurality of support braces including a first set of supportbraces attached to a first pair of sidewalls and a second set of supportbraces attached to a second pair of sidewalls, the first set of supportbraces extending in a plane direction transverse to the second set ofsupport braces.
 5. The system of claim 2, wherein the first containerfurther comprises a plurality of support members attached to respectivebottom surfaces of the first plurality of ramps, the plurality ofsupport members extending downwardly toward the bottom to support theramps, and the plurality of support members extend in a substantiallyhorizontal position.
 6. The system of claim 2, wherein each of the firstand second containers includes a container frame structurally arrangedto support another container when filled with large volumes of proppantand positioned in a vertically stacked arrangement thereabove such thateach of the first and second containers is structurally adapted tosupport the other container when the proppant is positioned therein. 7.A modular container system structurally strengthened to transport andstore large volumes of proppant effectively therein to supply to afracturing site, the system comprising: a first container comprising: afirst top, a first bottom having a first outlet formed therein to allowlarge volumes of proppant to flow therefrom when the outlet is in anopen position, a first plurality of sidewalls coupled to the first topand first bottom, so as to define a first interior volume of the firstcontainer thereby to store the proppant therein, the proppant having asubstantially spherical shape and a tightly graded particledistribution, a first plurality of ramps downwardly inclined andextending inwardly from the first plurality of sidewalls to direct theproppant toward the first outlet when the proppant is stored therein,and a first hatch movable toward the second container to transition thefirst hatch to the open position to allow proppant to flow from thefirst outlet; a second container adapted to be positioned below thefirst container, the second container comprising: a second top having anopening formed therein, a second bottom having a second outlet formedtherein to allow large volumes of proppant to flow therefrom when in anopen position, a second plurality of sidewalls coupled to the second topand second bottom, so as to define a second interior volume of thesecond container thereby to store the proppant therein, the proppanthaving a substantially spherical shape and a tightly graded particledistribution, a second plurality of ramps downwardly inclined andextending inwardly from the second plurality of sidewalls to direct theproppant toward the second outlet when the proppant is stored therein,and a second hatch movable toward the first container to transition thesecond hatch to an open position, each of the first and secondcontainers includes a container frame structurally arranged to supportanother container when filled with large volumes of proppant andpositioned in a vertically stacked arrangement thereabove such that eachof the first and second containers is structurally adapted to supportthe other container when the proppant is positioned therein.
 8. Thesystem of claim 5, further comprising a conveyor positioned below thesecond outlet such that proppant exiting the second container throughthe second outlet is deposited on the conveyor and transported away fromthe second container.
 9. The system of claim 5, wherein one or more ofthe first and second containers includes a first plurality of structuralsupports comprising a first plurality of support braces, the firstplurality of support braces including a first set of support bracesattached to a first pair of sidewalls and a second set of support bracesattached to a second pair of sidewalls, the first set of support bracesextending in a plane direction transverse to the second set of supportbraces.
 10. The system of claim 5, wherein the first container furthercomprises a plurality of support members attached to respective bottomsurfaces of the first plurality of ramps, the plurality of supportmembers extending downwardly toward the bottom to support the ramps, andthe plurality of support members extend in a substantially horizontalposition.